Coaxial cables generally include a central electrical conductor surrounded by a first dielectric or insulator. The central conductor is often made of copper, and the insulator may be formed from a foam or plastic. A sheath of braided metal strands and/or a metal foil is formed on the outer surface of the insulator to form an outer conductive shield. This sheath forms a ground shield and can be applied in various thickness which are known as single, double, and triple foil cable. The sheath in turn is surrounded by an outer insulating jacket to physically and electrically isolate the inside of the cable from the surrounding environment.
Coaxial cables are conventionally terminated with connectors that allow the cables to be connected to other cables and/or electrical devices. In order to install a connector at the end of a length of coaxial cable, the end of the coaxial cable must first be prepared to receive the connector. To prepare a coaxial cable, part of the outer insulating jacket is stripped from one end of the cable to expose a length of the metal conductive shield. Then, portions of the metal shield and the dielectric insulator are removed to expose a section of the central electrical conductor. The prepared end of the coaxial cable thus comprises a length of metal-shielded dielectric material projecting out of the jacket and a length of central conductor projecting out of the dielectric material.
A coaxial cable 100 is illustrated in FIG. 1 in the process of being inserted into a conventional connector 102, which may comprise, for example, a conventional F6 coaxial connector. The coaxial cable 100 includes an outer jacket 104 and a braided wire layer 105 and a layer of metal foil 106 between the outer jacket 104 and an insulating layer 108. The braided wire 105 is illustrated in FIG. 2 but omitted from the remaining figures for clarity. A central conductor 110 projects from an end of the exposed insulating layer 108. The connector 102 includes a shell 112 having an interior 114, and the shell 112 is formed from a sleeve 116 and a body 118. The shell 112 includes a first end 120 having a first end opening 122 formed in the sleeve 116 and a second end 124 having a second end opening 126 formed in the body 118. A nut 128 is connected to the body 118 at the second end 124 of the shell 112. A post 130 is formed of a base 132 and a tube 134, the tube 134 having an interior 136 and an end 138 with an aperture 140 at the end 138. The post 130 is pressed into the second end 124 of the shell 112 and retains the nut 128. The base 132 is mounted against the second end 124 of the shell 112 so that the tube 134 projects into the interior 114 of the shell 112 toward the first end opening 122. In this clamped position, the end aperture 140 of the tube 134 is located inside the shell 112 a distance from the first end opening 122.
As will be apparent from FIG. 1, the insulating layer 108 of the coaxial cable 100 must be inserted a distance into the interior 114 of the connector 102 before it contacts the end 138 of the post 130. Once the insulating layer 108 is inserted into the connector 102, however, a person attaching the connector 102 to the coaxial cable 100 can no longer see the end of the insulator 108. The presence of the folded back braided foil 105 further blocks the view of the interior of the connector 102. A user therefore must align the insulator 108 and its metal foil layer 106 with the aperture 138 of the tube 134 by feel. If the alignment is not precise, the foil layer 106 at the end of the insulating layer 108 may be damaged, and a damaged section 142 of the metal foil layer 106 is illustrated in FIG. 1. This damaged section 142 may adversely affect the performance of the connector 102 by causing direct and/or intermittent short circuits when the insulator 108 is later properly inserted into the interior 136 of the post 130 or may make it impossible to properly connect the coaxial cable 100 to the connector 102 and thus require that the end portion of the coaxial cable 100 be cut off and prepared again for a second attempt at attachment to the connector 102.
It would therefore be desirable to provide a connector that connects to a coaxial cable in a manner that substantially avoids the forgoing difficulties.